They've got flexibility to do stuff now. Like trade Bosa.
Per Spotrac, the Chargers converted ~$16M in salary and $5.5M roster bonus to a signing bonus for Mack to generate $10.7M in cap savings. I think that means they added a void year for 2025, meaning Mack will still be a UFA after 2024, but the Chargers will take a $10.7M dead cap hit for him in 2025. Unless the sign him to a contract extension before then.
I believe this means that he is no longer a trade candidate, since trading him this year would now save only $1.5M against the 2024 cap. They would need to get a real haul to make that trading him worth it, and it seems unlikely a team will want to give a haul for him now. Although I suppose it is worth noting that a team acquiring him now would only owe him ~$1.5M in salary in 2024 and nothing more. He would certainly seem to be an incredible value to an acquiring team. But... I can't see a team giving up a 1st or 2nd round pick for him despite that, and I think he is more valuable playing for the Chargers than a 3rd round pick or later.
Now that Mack is set to be a UFA after this season (as is Edge Rumph for whatever that's worth), combined with his age, I'm skeptical they want to trade Bosa. That would mean next season, out of current players expected to make the 2024 final 53 man roster, only Tuli would remain. Again, unless they want to extend Mack for his age 34 (and beyond?) season(s).
In addition, trading Bosa right now is selling low on him. IMO it is more likely that he will be more valuable next offseason after playing under the new coaching staff. Odds are he will be healthier, and he ought to play well under a better defensive staff and with Mack and Tuli also in the edge group.